1. Field of the Invention
This invention pertains to high-speed conveyors, and more particularly, to conveyors of the type used in conjunction with a strapping machine especially where the strapping machine is strapping unstable articles such as stacks of newspaper and for compacting the stacks at a strapping location on the strapping machine.
2. Description of the Prior Art
Strapping machines heretofore known have been unable to move stacks of paper through the strapping station of the machine at very high speeds. One of the reasons is the fact that the stack of newspapers is very unstable requiring that it be accelerated and decelerated slowly. One attempt to provide more stability to the stack has been to place a spring biased wheel on the top of the stack to hold the stack tightly against the lower conveying surface. Another technique has been to place a second conveyor on the top of the stack and to attempt to drive both of the conveyors synchronously at the same acceleration rates. Neither of these techniques has proven successful.
Still a further problem with strapping machine is that frequently the stack is not perfectly rectangular but rather is bowed up at the bottom because of inserts in the stack. This makes rapid conveying of such stacks very difficult.